Psychosis-predominant neuropsychiatric lupus in a severely malnourished adolescent: a diagnostic challenge.

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a rare but severe manifestation of systemic lupus erythematosus in adolescents, with psychosis-predominant presentations occurring in approximately 5-12% of pediatric cases. Such manifestations may precede or obscure classic systemic features, often resulting in diagnostic delays and initial misattribution to primary psychiatric or infectious etiologies. We present the case of a previously healthy 19-year-old female who developed acute psychosis characterized by paranoia, auditory hallucinations, disorganization, and suicidal ideation over five days. Immunosuppressive therapy was initiated with pulse-dose methylprednisolone, followed by intravenous immunoglobulin and rituximab. Early consideration of autoimmune etiologies and a multidisciplinary approach, including rheumatology, psychiatry, neurology, and nutrition, are essential to optimize outcomes in this vulnerable population. The patient's limited psychiatric response despite immunologic improvement underscores the delicate balance between prompt immunosuppression and the neuropsychiatric risks associated with corticosteroid therapy. This case highlights the diagnostic challenges of psychosis-predominant NPSLE in adolescents complicated by nutritional and infectious factors, whilst emphasizing the importance of early recognition of autoimmune etiologies and multidisciplinary management for optimal outcomes.